Hibiscusleavesis the Latin name for the marshmallow plant; meraukensis is for the Merauke area in New Guinea where the type specimen was collected.

This plant occurs in northern Australia, north of what would be virtually a straight line running from Townsville to just north of Derby in north-western Western Australia. It also occurs on many of the offshore islands, and in PNG. A specimen of the plant was collected by Banks and Solanderduring Cook’s voyage up the east coast of Australia in 1770; it is not clear whether they found it at Cape Grafton or on Palm Island.

It is usually found growing on clay flats, in flood plains, along creeks, and among sandstone rocks. The plant photographed was growing in the waste land near the industrial area in Nelly Bay, not far from the junction of Yates Street and Compass Crescent. What immediately strikes the eye on seeing this plant in bloom is the strong similarity of its flower to that of the rosella itself, Hibiscus sabdariffa, although this plant’s flowers are larger.

in budflowerThis is a small to medium annual shrub that grows up to about 2 m in height. Plants appear during the tropical wet season, and die off during the dry season that follows.

The leaves are hairy when young and quite large, up to 18 cm long by 10 cm, or even more, wide. They are very variable, and often both lobed and unlobed leaves are found on the same plant. There are usually one or more conspicuous slit-like nectaries near the base of the midrib or basal veins, on the underside of the leaf blade. The leaves are usually scabrous on both surfaces.

The flowers are about 10 cm in diameter, of typical hibiscus shape. They are generally white, but can also be various shades of pink and mauve. As with most members of the Hibiscus genus, the flowers are short-lasting, for only 1 or 2 days. However, new flowers continue to open over a long period, as long as the plant is able to draw on sufficient water. The flowers are followed by seed capsules containing a number of seeds.

fruit formingripe fruit with seedsThe wild rosella has been little cultivated, and does not seem to be well known even among native plant enthusiasts. This is a pity, as it is an attractive and quick-growing species for tropical and possibly sub-tropical climates. Although it is usually an annual, it can be readily propagated. Propagation from seed is relatively easily, and abrasion or soaking of the seeds before planting will usually hasten germination. Cuttings also strike readily, particularly if they are taken on an angle through a node, and a rooting hormone applied.

Pests are generally few, but, in common with the exotic Hibiscus cultivars, it can be affected by the hibiscus beetle. These are notoriously difficult to control because of their hard outer shell and their tendency to shelter out of reach within flower petals. The beetles cause premature flower fall. There are almost as many strategies for controlling these beetles as there are gardeners. Most agree that picking up fallen blooms each day helps reduce the number of beetles. I understand that white or yellow ice-cream containers filled with soapy or detergent water and placed beneath the plants will trap a significant number of adult beetles. It is suggested that the traps should be emptied every few days and refilled with a fresh solution.